Fastening device



Nov. 8, 1949 E. M. GREEN 2,487,330

' f FASTENING DEVICE Fild Aug. so, 194s.

ATTORNEi/cy.

Patented Nov. 8, '1949 FASTENING DEVICE Emmet M. Green, Los Angeles, Calif.

Application August 30, 1943, Serial No. 500,493

3 Claims. 1

This invention relates to improvements in fastening devices. i

The main objects of this invention are:

First, to provide a fastening device comprising a screw element and a nut element in which the screw element may be engaged with the nut element with a partial rotating movement of the screw element and one which at the same time is very secure.

Second, to provide a fastener device in which the nut element is springable, acting to provide effective longitudinal retaining engagement with the screw element and locking the screw element in its engaged position.

Third, to provide a fastener device having these advantages in which the screw element may be very quickly and easily engaged with the nut element, is effectively retained, and at the same time may be easily and quickly released and replaced as occasion may require.

Fourth, to provide an improved fastening device embodying these features and advantages in which the parts or elements may be economically and rapidly produced.

Fifth, to provide an improved screw element adapted to be engaged with a coacting nut element with a halfturn of the screw element and to be effectively retained by a screw element having yieldable locking members.

Sixth, to provide a fastener nut element for use with a screw fastener element which may be economically and rapidly produced or manufactured from sheet metal stock.

Seventh, to provide a fastener device in which the only change required to adapt .it to different thicknesses of work is to lengthen or lshorten the screw element.

Objects relating to details and economies of the invention will appear from the description to follow. The invention is defined and pointed out in the claims.

Preferred embodiments of the invention are illustrated in the accompanying drawing, in which:

Fig. 1 is a rear view of a fastener device embodying my invention applied to a piece of work and with the screw element in engagement with the nut element.

Fig. 2 is a sectional view through the work on line 2--2 of Fig. 1 partially showing the fastener device in elevation.

Fig. 3 is a fragmentary view through the fastener device and the work on a line corresponding to line 3-3 of Fig. l, the screw element being shown in full lines.

Fig. 4 is a fragmentary view partially in section on line 4-4 of Fig. 3 showing further details of the fastener device, the screw element and the central portion of the fastener element being shown in full lines.

Fig. 5 is an end elevation of the screw element of my fastening device showing the relation of the outer end of each of the double threads to the flattened tip.

Fig. 6 is a plan view of the blank shown on a small scale from which the nut element of my fastening device is formed.

While my fastener device is capable of wide adaptation and use, I have illustrated it in one adaptation having wide use, namely, the fastening of superimposed pieces of work I and 2, I being the inner or foundation member of the work and 2 the outer facing or piece of work which is superimposed on and secured to the foundation. Such structures are widely used in airplane structures and various types of structures.

The work member I is provided with a conically frustrum-shaped flanged opening 3 therein, the work member or element 2 having a correspending anged opening 4 therein, the anges being shown in nested relation. If desired, a grommet 5 may be provided for the outer member 2. 'Ihese flanges about the openings are commonly called dimples It will be understood that my fastener device is not concerned with these details. However, the flange 4 does provide a countersink for the tapered head 6 of the screw fastener element 1.

The head 6, as illustrated, is provided with a tool slot 8 extending transversely across the same; it will be obvious that any desired form of tool slot or recess or projection can be provided.

The stem or shaft 9 of the fastener element 'I is preferably cylindrical and terminates in a flattened -tip IIl of substantial length and width and preferably having a rounded end I I. The width of this tip` I0 is preferably the same as the diameter of the stem or shaft 9. The stem or shaft is provi-ded with double threads I2, the outer end I3 of each thread I2 is shown in Fig. 5 and the central portion of one thread I2 is shown between the end portions of the other thread I2 in Fig. 3, the threads in the preferred embodiment being of substantial depth and projecting from the surface of the stem instead of being cut or otherwise formed in the stern.

These threads I2 have transversely tapered 914i??? @nds I3 which terminate on opposite sides 3 of the stem and preferably adjacent the edges of the attened tip, see Figs. 2, 3 and 5. The advantage of this will be pointed out as the description proceeds.

The fastener element I4 of the embodiment illustrated is formed from a single piece of spring sheet stock, the blanks being shown at I4, Fig. 6. This fastener element has a central opening I5 adapted to receive the stem of the screw element with slots IGieXtending-'oppositely from the opening andlongitudinahy. of the fastener element, these slots terminating adjacent the attaching ears I 1 which are adapted to receive the rivets I8 securing the fastener element to the..work.I although it is evident that the ears might be otherwise secured, or in some instancesfmerely held until the screw fastener element is engaged.

The fastener element is Agenerally''rearv/'ardly bowed and the portions I 9 thereof constitute thread engaging members, being oppositely inclined orI pitchedato effectively. coactwiththe threads on .opposite .sides of the screw element, as shown.at.I9"in Figs...3` andA.. These thread engaging` members .Ilarefsubstantially rigid in effect but they may bespringable tosuch an extent as to provideeifective:engagement with thethreadsandecure.axial. stress on the screw element. 4 Thisinsures .eifective and ready engagement of the parts and compensates for tolerances and, inaccuracies. in manufacture. 'Ihe screw element isineiectrigidly secured against axial stresses when the parts are in engagement.

The thread. engagingmembershave loop-like or bowed springarms ZILextending oppositely from their outer edges 23, these=armsbeing brought inwardly to an. opposedsrelation relative to the flattened. tip of. thefscrew. element and preferably terminating in .rearwardlyturned' curved ngers 2I whichspringably receivethe-flattened tip I0 betweenthern. The-curvaturemf the fingers extends or. merges into the arms at. 22 lproviding a forwardly facing throat having curved walls which coact, with the-curvedend- II of the screw element in facilitatingy the entrance of the attened` tipbetween thengers and the seating i of the screw-element. The-springatms 2S being mounted; on thebuter edges -of the springable thread engaginglmembers YISJ .and being" disposed toy movebodily in -a-.planeincommon with the axis of thescrewelement facilitates forcing the ends ofthe .arms into-tight engagement with the flattenedtipof the screw element when the inner edges -of the threadl engaging members yare inwardly canted upon -turning ythevscrew element into La tightened locked position.

Thethreadengaging members. are laterally springableto receive-.thescrew element and also tdSpringabIysupport'the arms, thatis, as the threaded fastener element is manipulated to seating4 position; the threadengaging members may spring outwardlynor laterally .aswell as the arms being-sprung; With the double'threads, thethreadedifastener element; is eiectively seated by a. rotating ,'snapi action,` nowmatter in what positionit may .be presentedto the fastener elementx. 'Ioseat .the-iscrewtelement,v all the 'workmanfor roperatorr-is*l required to do-is to insert the threadielement' and exert someaxial: and rotative forces The.-tipcoacting'.with the spring arms assistsl ini rotating yori guiding; the. screw element so 'thatthe threads. are eectively 'positioned to engage the ythreadf engaging members l.and the spring lockinggiarms coact4 in the-inalrotating of the screwelernent,withia.snapelikeaction `to seating;position:fA Thesearmsnot; only serve as locking members but they are of importance in the quick seating of the screw element or in the assembly of the fastener.

In the embodiment of my invention illustrated the parts may be rapidly and economically manufactured; the fastener elements are quickly assembled by a partial rotative and axial thrust movement, the engagement in effect being a snap action engagement. The fastener is highly effective andit cannot be disengaged except with the reverse rotation ofi-the screw. The locking features prevent that occurring without manual manipulation.

Another very valuable feature is that to adapt the fastener device of my invention to different gage or thickness of work it is only necessary to lengthen or shorten the screw element. Threads of about221/2 degree pitch or angle are found to be'very practical.

I have illustrated and described a simple and practical .embodiment or adaptation of my invention. I have not illustrated or described other embodimentsor.adaptations which I contemplate as. it is-believed .this vdisclosure willenable those skilledin vtheartto embodyor adapt my invention. as may bedesired.v

Having, thus described my invention, whatI claimas new and desire. to: secure byvLetters Patent is:

11. .A/.fastener element for use. with va screw threaded `fastener .element having a flattened tip comprising a one-piece rearwardly bowednut element of springable'material` having `attaching ears at the ends thereofcand a.=central screw element` receiving opening.` therein and longitudinaly slots extendingoppositely from said opening to points adjacent I.the ears the-portions of the element onopposite sidesof ythe screw opening constituting thread engaging-members and being oppositely Apitchedto-coact with threads on opposite. sides of a screw element, said thread engagingA members. havingloop-like spring arms extending,v oppositely ,from .their outer edges and terminating in rearwardly. extending opposed fingers adapted to springably receive the flattened. tip. of ascrew. element between them, said fingers merging inta-the arms to provide a forwardly expanding throat, facilitating. the-'emtrance of the iiattened.` tip ofthe screwelement between. them,4 .said .thread .engaging members being laterally springable and .springably supporting.saidarms.

2. A fastener-element for use with a screw threaded fastener element having a fiattened'tip comprising a one-piece rearwardly bowed nut element i of springable materialr having attaching ears at the ends thereof and aA central screw element receivingopening therein and longitudinal slots extendingfoppositelyfrom said opening to points adjacent the earsthe portions of the element on opposite sides of the screw opening constitutingl threadV engaging members'and being oppositely pitched to coa-ctwiththreads on opporsite sides of a screw element, said thread en'- gagingA membersfhaving loop-like spring arms extending oppositelyjfrom their outer edges and terminating in. rearwardly extending opposed ngers adapted to springably receive the-flat@ tened tip'of` a-:screw elementbetweenthem when thexscrew element'is partially :seated 'andacting to urge the screw element to fully seated'position 3. A bowed` nut fastener elementof springable material adapted for use with a threaded-'fastener element having a flattene'dtip, the saidniit fast-Y ener element having a screw `velement receiving opening therein and slots extending oppositely from said opening, the portions of the element on opposite sides of said opening constituting thread engaging members and being oppositely pitched to coact with threads of a screw element, said thread engaging members having spring arms eX- tending oppositely from their outer edges and terminating in rearwardly extending opposed lingers adapted to springably receive the flattened tip of .a screw elementl between them, said spring arms being disposed generally in a common plane with each other, said plane being disposed substantially at right angles to the plane of the screw element receiving opening and crossing said opening.

EMMET M. GREEN.

REFERENCES CITED The following references are of record in the fie of this patent:

Number Number UNITED STATES PATENTS Name Date Tinnerman Sept. 26, 1933 Richardson Dec. 12, 1939 Shippee et a1 June 18, 1940 -Zahodiakin Oct. 14, 1941 Reeser Apr. 14, 1942 Bedford, Jr. Dec. 29, 1942 Murphy Dec. 29, 1942 Murphy Feb. 2, 1943 Bedford, Jr June 22, 1943 Johnson Sept. 21, 1943 Green Sept. 12, 1944 Graham Apr. 23, 1946 Venditty May 4, 1948 FOREIGN PATENTS Country Date France July 3, 1939 

